Implied Probability Tool
Turn bookmaker odds into true probabilities for one or several outcomes.
How to Use This Calculator
- Pick your odds format: Decimal, Fractional, or American
- Enter odds for at least two outcomes (e.g., Team A and Team B)
- Add further outcomes if required (e.g., a draw in soccer)
- Read the implied probability per outcome, the total probability, and the bookmaker margin
When the total implied probability tops 100%, that excess is the bookmaker’s margin.
Formula
Implied Probability from Decimal Odds: Probability = (1 / Decimal Odds) x 100%
Bookmaker Margin: Margin = Total Implied Probability - 100%
No-Vig (Fair) Probability: Fair Probability = Implied Probability / Total Implied Probability
Frequently Asked Questions
What is implied probability?
Implied probability is the chance of an outcome as implied by the odds. It bakes in the bookmaker’s margin, so the total always comes out above 100%.
What is the bookmaker margin?
The bookmaker margin (also vig or juice) is the gap between the summed implied probabilities and 100%. That gap is the bookmaker’s built-in profit.
How do I find value bets?
When you reckon the true probability of an outcome beats the implied probability from the odds, that bet carries positive expected value.